Big swing in temperatures coming

The marine layer will thicken along the coast over the next couple of days, preventing daytime highs from rising above 68, which is seasonal. But we're in for a sharp change starting on Thursday, when high pressure starts to build over the western United States.

The National Weather Service says the temperature will hit 78 Thursday in San Diego and could reach 81 on Friday. The inland valleys and foothills could hit 90. The winds also will kick up on Thursday, gusting up to 50 mph inland, while the relative humidity falls below normal. Forecasters say the conditions will cause the danger of wildfires to spike in East County. A red flag fire weather watching is possible. The heat will last into Saturday, when cooler weather settles over the region.

Shore thing: Solspot.com says waves will be in the 3- to 5-foot range Monday and Tuesday in South County and about a foot smaller in North County. Sea surface temperatures have risen to about 63 degrees.